1. Field of the Invention
The present invention relates to knitting machines, and in particular, to an electrically controlled steering system which may replace a jacquard controlled mechanism.
2. Description of the Relevant Art
Typical jacquard control mechanisms utilize control elements which are needle formed slides disposed parallel to each other and have two stable or fixed positions. The striking surface for moving the needle formed slides is a hook disposed at one end thereof. Each slide is provided with a collar on the other end thereof which is coupled, by means of a harness string to the steerable element for example the displacement finger or steering element of a jacquard controlled warp knitting machine. A sinker hook is disposed perpendicular to the slider element. A knife edge is provided for the purpose of lifting the sinker hook during each working cycle. During this lifting movement those sinker hooks which are not to be displaced are moved to a secondary position where they cannot co-act with the knife edge. This arrangement requires synchronization of many parts and is difficult to maintain in proper alignment for long periods of time. In addition, since the parts must move over long distances, the speed of operation of the machine is severly limited.
Also, in order to reduce the strain on the harness strings which are coupled between the slider and the displacement finger the mechanism must be placed high above the warp knitting machine in order to reduce the angle of the harness strings so that they approach as close to a straight line as possible thereby avoiding the friction losses as the strings go around corners.
The present invention overcomes the shortcomings of the known devices by providing an electromagnetically controlled apparatus which may be mounted in close proximity to the knitting machine since the steering mechanism is small in size and may be mounted relatively closely to the guidebars. The harness strings may be made much shorter than heretofore known and extend in almost a straight line to the steering element which is used to deflect the individual guides. With the smaller number of components utilized in the instant invention, the machine is capable of higher rates of speed and more reliable operation.
The control element in the instant invention is rotatably positioned and is activated by a synchronized arrangement over a given working area in one direction of rotation and is caused to return over the same angle by a return spring, thereby utilizing much less volume than other known mechanisms.
The construction utilized in the instant invention does away with sinker hooks and the corresponding knife edges. The desired movement of the steerable elements is obtained solely by the rotation movement of the control element and not the lateral movement perpendicular to the slider. Each control element requires only one connection point. The dimensions of the rotatable control elments of the instant invention can be held substantially smaller than the dimentions of the needle shaped control elements and their correspondingly crossing sinker hooks. Since the bulk of the control elements are provided with a very small displacement from the axis of rotation, very small moments of force are involved, thereby permitting much higher speeds of operation. With the present apparatus it is advantageous to have the control elements biased by a spring in a conventional manner. The spring presently utilized as a return spring for the control element may again be used in the present invention, thus reducing the number of new elements required.
The steering mechanism control and the steering or deflection element may be connected by a harness string. Other means of transferring the movement of the steering mechanism to the steerable or deflecting element may be utilized by those knowledgable of the art, and it is to be considered within the scope of the present invention.
When utilizing conventional steerable elements such as displacement fingers for a plurality of guides they are normally coupled to a jacquard mechanism, via a plurality of harness strings and is desirable to provide the corresponding control elements side by side and directly above the displacement elements. This may be readily done with the present configuration. However, heretofore, the control arrangement was located in the central position of the warp knitting machine and was connected to the displacement elements by the harness strings which had to be displaced over varying angles. This required a substantial separation between the control mechanism and the displacing elements, generally in the order of about two to three meters. Otherwise, it would have been necessary to provide very sharp angles to the harness strings appearing at the ends of the machine thereby causing substantial friction and unreliability. A space of two meters above the knitting machine generally required a specially constructed building with high ceilings. Utilizing the construction as set forth in the instant invention, this space may be reduced considerably, in fact the control steering mechanism is disposed right above the knitting machine and thus, the machine may be placed in a building which has a normal ceiling height.